Heterogeneously Catalyzed Esterification of FFAs in Vegetable Oils

Abstract

The production of methyl esters (biodiesel) from free fatty acids (FFAs) contained in vegetable oils was studied using a heterogeneous acid catalyst. The feedstock was a by-product of a vegetable oil refinery. The experiments were performed in a batch reactor, in a temperature range of 363.15-393.15 K, with an initial molar ratio of methanol to FFAs of 6.6/1, while the catalyst mass was fixed at 2 wt % of the total vegetable oil mass. A technical kinetic model has been developed which accounts for the reversible esterification reaction. Kinetic parameters were determined by fitting experimental data to the model.

A heterogeneous acid‐catalyzed process for biodiesel production from enzyme hydrolyzed fatty acids

“…Hence, the assumption of absence of external and internal mass-transfer resistances in model development is confirmed because this reaction is established as kinetically controlled. [26][27][28] Pasias et al 17 used the same reaction model for the esterification of FFAs in vegetable oil with methanol using cationexchange resin as catalyst. They reported activation energies of forward and backward reactions of 70.34 and 37.93 kJ mol 21 , respectively.…”

“…15 This result is consistent with the literature reported. 15,17,24,25 Activation Energy. As aforementioned, the forward reaction rate and equilibrium constants depending on temperature are represented by the Arrhenius model (Eqs.…”

“…1,17,19,20 In this study, a pseudo-homogeneous model was therefore used to depict the kinetics of esterification of FFAs with methanol in the presence of cationexchange resin based on the following assumptions: (1) no internal and external mass resistance exist, 19 (2) sorption effect of involved species is neglected, and (3) whole system is taken into account as an ideal solution.…”

“…2 Acidic cation-exchange resin has also shown positive results in the esterification of oil containing a high level FFAs with methanol. 1,17 A route for biodiesel synthesis using ion-exchange resins as heterogeneous catalysts therefore appears certainly attractive. In this work, FFAs obtained from enzymatic hydrolysis of soybean oil by lipase are used as a feedstock to produce biodiesel by heterogeneous catalytic process.…”

Katalysatorscreening bei der Umesterung von Fetten und Ölen mit Ethanol

“…Üblicherweise werden natürliche Fette und Öle mit Methanol und alkalischen homogenen Katalysatoren umgesetzt, um Fettsäureme-thylester (FAME) mit der entsprechenden Spezifikation zu erzeugen. Heute werden bevorzugt raffiniertes Sojabohnen-, Raps-, Sonnenblumen-und Palmöl für Biodiesel eingesetzt [1]. Von Nachteil sind dabei die hohen Kosten des Einsatzöls.…”